[Custom Sheet] Fillable Drop Down Menus & Calculations

I know it's possible to have a button you can click that will open a drop down menu you can fill out, like in the D&D 5e sheet, but I have no idea how to do that.   I also know it's possible to click on that entry's title and have it post a description, but again no idea how to do that. Finally, I don't know if this is possible, but I want to have a button I can have my players click that will roll a die (/roll 1d100, I know that part), as well as look up a few numbers, add them together, and post it along with the roll. Can someone point me to how those would be coded, if they're possible, please?

You'll almost certainly be able to find out how to do what you want here: <a href="https://cybersphere.me/roll20/" rel="nofollow">https://cybersphere.me/roll20/</a> or in the roll20 wiki , but if you posts specific examples of what you want, we might be able to help more. For the last one, you can include any macro in a roll button, like this: &lt;button type="roll" name="roll_example" value="/roll 1d100+@{strength}"&gt;Strength Roll&lt;/button&gt; If in question 2, you mean post into chat, it will be a variation of this (with maybe a custom rolltemplate to style it), or Custom Roll Parsing, which is just a more sophisticated version of this. Question 1 sounds like a select or an input with an optionlist. More details are needed!